Roberta McLauglin photographs an exhibit of shoes in remembrance of people who have jumped from the Golden Gate Bridge (AP/Noah Berger)

Crowds gathered along San Francisco's waterfront and the bay was crowded with pleasure boats, tugs and other vessels as the city celebrated the 75th anniversary of the Golden Gate Bridge.

Tens of thousands of people were expected to flock to the area to enjoy a host of events taking place along a section of waterfront stretching from Fort Point south of the bridge to Pier 39 along The Embarcadero.

At least several thousand people had gathered along the waterfront by Sunday night, said Mary Currie, public affairs director for the Golden Gate Bridge, Highway and Transportation District.

"Everyone is biking and walking and looks very happy," she said. "We're off to a great start."

Resident Daniel Sutphin and his family were among those enjoying the day and the views of the bridge. "It's such an iconic structure, depending on the day or the hour, it just looks like it changes continuously," he said as he walked through the Fort Point area with his wife and their three young children.

Since it opened in 1937, more than two billion vehicles have crossed the 1.7-mile-long bridge named after the Golden Gate Strait, the entrance of water to San Francisco Bay from the Pacific Ocean, and championed by engineer Joseph Strauss in the 1920s.

Because of the crowds expected and with no parking available near the bridge, officials were urging people to take public transport to the events.

The California Highway Patrol was shutting down traffic across the bridge for a monumental fireworks display.

But in a stark contrast to the thousands of celebrants, members of the Bridge Rail Foundation, an organisation dedicated to stopping suicide jumps, erected a display of 1,558 pairs of shoes, representing the number of people who died in leaps from the bridge since it opened in 1937.

"It's a symbol of how deep and serious this problem has been," said Paul Muller, a spokesman for the group. "We're still losing 30 to 35 a people a year off the bridge."